System and method for providing universal synchronization signals for new radio

ABSTRACT

A method and apparatus are provided. The method includes, but is not limited to, receiving a universal synchronization signal (USS) including a universal primary synchronization signal (UPSS) and a universal secondary synchronization signal (USSS), wherein the USS is coded using a mother code which is extended to m resource blocks (RBs) and n orthogonal frequency division multiplexing (OFDM) symbols and a code cover of m RBs and n symbols is applied to the mother code, determining a cell identity based on the USS, determining a frame timing based on the USS, and connecting a user equipment to a network using the cell identity and the frame timing.

PRIORITY

This application is a Continuation of U.S. patent application Ser. No.15/353,274, filed on Nov. 16, 2016, which claims priority under 35U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/377,372,which was filed in the U.S. Patent and Trademark Office on Aug. 19,2016, the entire content of each of which is incorporated herein byreference.

FIELD

The present disclosure generally relates to a method and apparatus, andmore particularly, to a method and apparatus for providing universalsynchronization signals for new radio (NR) access technology.

BACKGROUND

Users of electronic devices require increasing functionality andperformance in applications, services and the communication networksused by electronic devices. Fifth generation (5G) wireless communicationnetworks, also referred to as new radio (NR) access technology, providesincreased performance and capacity for data and voice communications forusers and supports multiple new communication services such as enhancedmobile broad band (eMBB), massive machine type communication (mMTC),ultra reliable low latency communication (URLLC), and narrow-bandInternet of things (NB-IoT). The 3rd generation partnership project(3GPP) radio layer 1 (RAN1) group supports the specification ofstandards that enables these new communication services. Each of theservices is targeted towards achieving different goals depending on theapplication. For example, eMBB targets high data throughput and capacityto provide smartphone and tablet users with services such as highdefinition video delivery, mMTC targets maximizing the number ofconnections for a very large number of small and power-constraineddevices, where each device infrequently transmits a low volume oflatency insensitive data, and NB-IoT is targeted towards low powerdevices for applications such as smart cities, connected industrialdevices and mobile health. To support multiple communication serviceswith a single standardized specification, re-designing ofsynchronization signals is required. 3GPP has determined the basicprinciple for the design of NR synchronization signals to be flexiblyconfigurable resource allocations and sharing of synchronization signalsamong multiple numerologies.

SUMMARY

An aspect of the present disclosure provides a method which includesreceiving a universal synchronization signal (USS) including a universalprimary synchronization signal (UPSS) and a universal secondarysynchronization signal (USSS), wherein the USS is coded using a mothercode which is extended to m resource blocks (RBs) and n orthogonalfrequency division multiplexing (OFDM) symbols and a code cover of m RBsand n symbols is applied to the mother code, determining a cell identitynumber based on the USS, determining a frame timing based on the USS,and connecting a user equipment to a network using the cell identitynumber and the frame timing.

Another aspect of the present disclosure provides an apparatus whichincludes a receiver configured to receive a universal synchronizationsignal (USS) including a universal primary synchronization signal (UPSS)and a universal secondary synchronization signal (USSS), wherein the USSis coded using a mother code which is extended to m resource blocks(RBs) and n orthogonal frequency division multiplexing (OFDM) symbolsand a code cover of m RBs and n symbols is applied to the mother code,and a processor configured to determine a cell identity from the USS,determine a frame timing from the USS, and connect a user equipment to anetwork using the cell identity and the frame timing.

Another aspect of the present disclosure provides a method ofmanufacturing a processor which includes forming the processor as partof a wafer or package that includes at least one other processor,wherein the processor is configured to receive a universalsynchronization signal (USS) comprising a universal primarysynchronization signal (UPSS) and a universal secondary synchronizationsignal (USSS), wherein the USS is coded using a mother code which isextended to m resource blocks (RBs) and n orthogonal frequency divisionmultiplexing (OFDM) symbols and a code cover of m RBs and n symbols isapplied to the mother code, determine a cell identity from the USS,determine a frame timing from the USS, and connect a user equipment to anetwork using the cell identity and the frame timing.

Another aspect of the present disclosure provides a method ofconstructing an integrated circuit, which includes generating a masklayout for a set of features for a layer of the integrated circuit,wherein the mask layout includes standard cell library macros for one ormore circuit features that include a processor configured to receive auniversal synchronization signal (USS) comprising a universal primarysynchronization signal (UPSS) and a universal secondary synchronizationsignal (USSS), wherein the USS is coded using a mother code which isextended to m resource blocks (RBs) and n orthogonal frequency divisionmultiplexing (OFDM) symbols and a code cover of m RBs and n symbols isapplied to the mother code, determine a cell identity from the USS,determine a frame timing from the USS, and connect a user equipment to anetwork using the cell identity and the frame timing.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the presentdisclosure will become more apparent from the following detaileddescription, when taken in conjunction with the accompanying drawings,in which:

FIG. 1 is a block diagram of an electronic device in a communicationnetwork, according to an embodiment of the present disclosure:

FIG. 2 illustrates a mapping of a primary synchronization signal tosubcarriers of resource blocks of an orthogonal frequency divisionmultiplexing (OFDM) communication system, according to an embodiment ofthe present disclosure;

FIG. 3A illustrates a mapping of a primary synchronization signal in afrequency division duplexing wireless communication system, according toan embodiment of the present disclosure;

FIG. 3B illustrates a mapping of a primary synchronization signal in atime division duplexing wireless communication system, according to anembodiment of the present disclosure;

FIG. 4 illustrates resources required for primary and secondary sidelinksynchronization signals in a device to device communication network,according to an embodiment of the present disclosure;

FIG. 5 illustrates a mapping of symbol and slot resources required forprimary and secondary sidelink synchronization signals in a device todevice communication network, according to an embodiment of the presentdisclosure;

FIG. 6A illustrates a mapping of primary synchronization signals in anarrow band Internet of things communication network, according to anembodiment of the present disclosure;

FIG. 6B illustrates a mapping of primary synchronization signals in anarrow band Internet of things communication network, according toanother embodiment of the present disclosure;

FIG. 7A illustrates a mapping of secondary synchronization signals in anarrow band Internet of things communication network, according to anembodiment of the present disclosure;

FIG. 7B illustrates a mapping of secondary synchronization signals in anarrow band Internet of things communication network, according toanother embodiment of the present disclosure:

FIG. 8 illustrates a mapping of universal synchronization signals formultiple new radio access technology communication services, accordingto an embodiment of the present disclosure;

FIG. 9 is a flowchart of a method of testing a processor configured todetermine universal synchronization signals, according to an embodimentof the present disclosure;

FIG. 10 is a flowchart of a method of manufacturing a processorconfigured to determine universal synchronization signals, according toan embodiment of the present disclosure; and

FIG. 11 is a flowchart of a method of connecting a user equipment to anetwork using a universal synchronization signal (USS), according to anembodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of thepresent disclosure are shown. This disclosure may, however, be embodiedin many different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the device and method to those skilled in the art.Like reference numbers refer to like elements throughout.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, it may be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. As used herein, the term “and/or”includes, but is not limited to, any and all combinations of one or moreof the associated listed items.

It will be understood that, although the terms first, second, and otherterms may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first signal may bereferred to as a second signal, and, similarly a second signal may bereferred to as a first signal without departing from the teachings ofthe disclosure.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to limit the present device andmethod. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” or “includes, but is not limited to”and/or “including, but not limited to” when used in this specification,specify the presence of stated features, regions, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, regions, integers,steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including, but not limited totechnical and scientific terms) used herein have the same meanings ascommonly understood by one of ordinary skill in the art to which thepresent device and method belongs. It will be further understood thatterms, such as those defined in commonly used dictionaries, should beinterpreted as having meanings that are consistent with their meaning inthe context of the relevant art and/or the present description, and willnot be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 is a block diagram of an electronic device in a networkenvironment, according to an embodiment of the present disclosure.

Referring to FIG. 1, an electronic device 100 includes, but is notlimited to, a communication block 110, a processor 120, a memory 130, adisplay 150, an input/output block 160, an audio block 170 and a newradio (NR) transceiver 180. The NR transceiver 180 may be included in acellular base station and includes, but is not limited to, a wirelesstransmitter and receiver.

The electronic device 100 includes a communication block 110 forconnecting the device 100 to another electronic device or a network forcommunication of voice and data. The communication block 110 providesNR, cellular, wide area, local area, personal area, near field, deviceto device (D2D), machine to machine (M2M), satellite, enhanced mobilebroad band (eMBB), massive machine type communication (mMTC), ultrareliable low latency communication (URLLC), narrow-band Internet ofthings (NB-IoT) and short range communications. The functions of thecommunication block 110, or a portion thereof including a transceiver113, may be implemented by a chipset. In particular, the cellularcommunications block 112 provides a wide area network connection throughterrestrial base transceiver stations or directly to other electronicdevices, using technologies such NR access technology, D2D, M2M, longterm evolution (LTE), fifth generation (5G), long term evolutionadvanced (LTE-A), code division multiple access (CDMA), wideband codedivision multiple access (WCDMA), universal mobile telecommunicationssystem (UMTS), wireless broadband (WiBro), and global system for mobilecommunication (GSM). The cellular communications block 112 includes, butis not limited to, a chipset and the transceiver 113. The transceiver113 includes, but is not limited to, a transmitter and a receiver. Thewireless fidelity (WiFi) communications block 114 provides a local areanetwork connection through network access points using technologies suchas IEEE 802.11. The Bluetooth communications block 116 provides personalarea direct and networked communications using technologies such as IEEE802.15. The near field communications (NFC) block 118 provides point topoint short range communications using standards such as ISO/IEC 14443.The communication block 110 also includes a GNSS receiver 119. The GNSSreceiver 119 may support receiving signals from a satellite transmitter.

The electronic device 100 may receive electrical power for operating thefunctional blocks from a power supply, including, but not limited to abattery. The NR transceiver 180 may be a part of a terrestrial basetransceiver station (BTS) (such as a cellular base station) and includea radio frequency transmitter and receiver conforming to 3GPP standards.The NR transceiver 180 may provide data and voice communicationsservices to users of mobile user equipment (UE). In the presentdisclosure, the term “UE” may be used interchangeably with the term“electronic device”.

The processor 120 provides application layer processing functionsrequired by the user of the electronic device 100. The processor 120also provides command and control functionality for the various blocksin the electronic device 100. The processor 120 provides for updatingcontrol functions required by the functional blocks. The processor 120may provide for coordination of resources required by the transceiver113 including, but not limited to, communication control between thefunctional blocks. The processor 120 may also update the firmware,databases, lookup tables, calibration method programs and librariesassociated with the cellular communications block 112. The cellularcommunications block 112 may also have a local processor or a chipsetwhich dedicates computing resources to cellular communications block 112and other functional blocks such as universal synchronization signalsrequired for cellular communication.

The memory 130 provides storage for device control program code, userdata storage, application code and data storage. The memory 130 mayprovide data storage for the firmware, libraries, databases, lookuptables, algorithms, methods, universal synchronization signalparameters, and calibration data required by the cellular communicationsblock 112. The program code and databases required by the cellularcommunications block 112 may be loaded into local storage within thecellular communications block 112 from the memory 130 upon device bootup. The cellular communications block 112 may also have local, volatileand non-volatile memory for storing the program code, libraries,databases, calibration data and lookup table data.

The display 150 may be a touch panel, and may be embodied as a liquidcrystal display (LCD), organic light emitting diode (OLED) display,active matrix OLED (AMOLED) display, and the like. The input/outputblock 160 controls the interface to the user of the electronic device100. The audio block 170 provides for audio input and output to/from theelectronic device 100.

The NR transceiver 180 may be included in a base station that is used toreceive, transmit or relay wireless signals. The NR transceiver 180 mayfacilitate communication with the electronic device 100 by sending,receiving, and relaying communication and universal synchronizationsignals to and from the electronic device 100. The electronic device 100may be connected to a network through the NR transceiver 180.

For example, the NR transceiver 180 may be a cell tower, a wirelessrouter, an antenna, multiple antennas, or a combination thereof beingused to send signals to, or receive signals from, the electronic device100, such as a smartphone. The NR transceiver 180 may relay the wirelesssignals through the network to enable communication with otherelectronic devices 100 such as user equipment (UE), servers or acombination thereof. The NR transceiver 180 may be used to transmit thecommunication signals, such as voice or data. The electronic device 100may receive and process signals including universal synchronizationsignals from the NR transceiver 180.

Based on the communication method, such as NR access technology, eMBB,mMTC, URLLC, NB-IoT, code division multiple access (CDMA), orthogonalfrequency division multiple access (OFDMA), third generation partnershipproject (3GPP) long term evolution (LTE), long term evolution advanced(LTE-A), fourth generation cellular wireless standards (4G), new radio,or fifth generation cellular wireless standards (5G), the communicationsignals may also have universal synchronization signals within thecommunicated information. The universal synchronization signals may beembedded within the communicated information at a regular time interval.

According to an embodiment of the present disclosure, the present systemand method provides a synchronization signal structure for transmissionof universal synchronization signals (USS) from the NR transceiver 180to the transceiver 113 of the electronic device 100. The USS of thepresent disclosure may be used simultaneously for multiple communicationservices including, but not limited to, eMBB, mMTC, URLLC and NB-IoT.The USS may be flexibly configured over a number of resource blocks(RBs) and a number of symbols transmitted from the NR transceiver 180 tothe transceiver 113 of electronic device 100. The USS may also providesynchronization signals for other communication services.

According to an embodiment of the present disclosure, the USS includes auniversal primary synchronization signal (UPSS) and a universalsecondary synchronization signal (USSS). The USS may have a mother codespanned over 1 RB and 1 symbol. The mother code may also be extended tom RBs over frequency and n symbols over time. The mother code is theoriginal code before puncturing. The 2-dimensional extended signals,where one dimension is frequency and the other dimension is time, may bea synchronization signal for eMBB that is transmitted across multipleRBs. In addition, 1 RB within m RBs may be assigned to NB-IoT. In longterm evolution (LTE), the dedicated RB for NB-IoT synchronizationsignals may not be located at the central 6 RBs, since the central 6 RBsare occupied for use in LTE. The present system and method shares theresources of m RBs assigned to universal synchronization signals suchthat 1 RB among m RBs may be used for NB-IoT.

According to an embodiment of the present disclosure, the values of mand n may be flexibly configured. For example, in LTE, the down-link(DL) synchronization signal uses 1 symbol in time and 62 subcarriers infrequency. In LTE, the sidelink (SL) synchronization signal is repeatedin time such that 2 symbols are used for synchronization resources.NB-IoT only considers 1 RB and 11 symbols for the synchronizationresources. In order to support multiple communication services with asingle universal structure, both m and n may be flexibly configured.

Since the USS includes multiple short sequences over frequency, it maybe extended to non-contiguous RBs. Synchronization in LTE and sidelinksynchronization such as in D2D only considers the central 6 RBs, andNB-IoT only needs to check pre-determined RB indices that may be locatedat non-central 6 RBs. The present system and method extends the mothercode (1 RB, 1 symbol) to non-contiguous RBs in order to universallysupport multiple communication services.

According to an embodiment of the present disclosure, the USS (includingthe UPSS and the USSS) includes sharing of mother codes over frequencyamong multiple services, extension of mother codes to time/frequencywith two dimensional code covers, and is applicable to non-contiguousRBs and orthogonal frequency-division multiplexing (OFDM) symbols withmother codes.

LTE has two downlink synchronization signals that a UE uses to obtainthe cell identity and frame timing of a cell the UE is attempting toconnect to. The two downlink synchronization signals include the primarysynchronization signal (PSS) and the secondary synchronization signal(SSS). There are a total of 504 unique physical cell identities. Theidentity number of a cell may be determined by Equation (1) as follows:

N _(ID) ^(CELL)=3N _(ID) ⁽¹⁾ +N _(ID) ⁽²⁾  (1)

where N_(ID) ⁽¹⁾ is the physical cell identity group (0 to 167), whichis detected by the SSS and N_(ID) ⁽²⁾ is the cell identity within thecell identity group (0 to 2) which is detected by the PSS. The PSS maybe based on a frequency domain Zadoff-Chu (ZC) sequence and may have alength of 62 symbols. The PSS may be determined by Equation (2) asfollows:

$\begin{matrix}{{{{d_{u}(n)} = {{e^{\frac{{- j}\; \pi \; {{un}{({n + 1})}}}{63}}\mspace{14mu} {for}\mspace{14mu} n} = 0}},1,\ldots,30}{{{d_{u}(n)} = {{e^{\frac{{- j}\; \pi \; {u{({n + 1})}}{({n + 2})}}{63}}\mspace{14mu} {for}\mspace{14mu} n} = 31}},32,\ldots,61}} & (2)\end{matrix}$

FIG. 2 illustrates a mapping of a primary synchronization signal tosubcarriers of resource blocks of an orthogonal frequency divisionmultiplexing (OFDM) communication system, according to an embodiment ofthe present disclosure.

Referring to FIG. 2, the PSS is mapped to the central six resourceblocks 200 over 72 subcarriers. In the frequency domain, the PSS and SSSoccupy the central six resource blocks 200, irrespective of the systemchannel bandwidth, which allows the UE to synchronize to the networkwithout prior knowledge of the allocated bandwidth. The synchronizationsequences use 62 sub-carriers in total, with 31 sub-carriers 202 mappedon each side of the DC sub-carrier 204 which is not used and leaves 5sub-carriers reserved 206 at each end of the 6 central RBs 200.

FIG. 3A illustrates a mapping of a primary synchronization signal in afrequency division duplexing orthogonal frequency division multiplexing(OFDM) communication system, according to an embodiment of the presentdisclosure.

Referring to FIG. 3A, in a 10 ms radio frame 300 of a frequency divisionduplexing (FDD) communication system, the PSS is mapped to the last OFDMsymbol 302 in slot zero 304 (subframe 0) and slot ten 306 (subframe 5).

FIG. 3B illustrates a mapping of a primary synchronization signal in atime division duplexing orthogonal frequency division multiplexing(OFDM) communication system, according to an embodiment of the presentdisclosure.

Referring to FIG. 3B, in a 10 ms radio frame 310 of a time divisionduplexing (TDD) communication system, the PSS is mapped to the thirdOFDM symbol 312 in subframe 1 314 and subframe 6 316.

The SSS may be based on maximum length sequences (m-sequences). Anm-sequence is a pseudorandom binary sequence which may be created by acycling shift. The m-sequences may be generated using maximal linearfeedback shift registers and reproduce every binary sequence that may berepresented by the shift registers. Two binary sequences, each of length31, are used with two binary scrambling codes, each being assigned tothe first and second SSS sequence, respectively. The SSS is transmittedin the same subframe as the PSS but in the OFDM symbol that immediatelyprecedes the PSS. The SSS is mapped to the same subcarriers (middle 72subcarriers) as the PSS.

FIG. 4 illustrates resources required for primary and secondary sidelinksynchronization signals in a device to device (D2D) communicationnetwork, according to an embodiment of the present disclosure.

In a device to device (D2D) network, when the electronic device 100 iswithin a coverage area of an NR transceiver 180, the same signals asPSS/SSS are used to perform synchronization. Referring to FIG. 4, whenthe electronic device 100 is not within a coverage area of an NRtransceiver 180, two signals may be used for synchronization which aredefined as the primary sidelink synchronization signal (PSSS) 400 andthe secondary sidelink synchronization signal (SSSS) 402. The primarysidelink synchronization signal (PSSS) 400 and the secondary sidelinksynchronization signal (SSSS) 402 may not be contiguous to the central 6RBs 404.

FIG. 5 illustrates a mapping of symbol and slot resources required forprimary and secondary sidelink synchronization signals in a device todevice (D2D) communication network, according to an embodiment of thepresent disclosure.

Referring to FIG. 5, both the PSSS and SSSS signals use frequency domainZadoff-Chu sequences and m-sequences, which are the same as LTE in thedownlink (DL) direction. They are also mapped to the central 6 RBs 500over 72 subcarriers with a length of 62 symbols. The PSSS is mapped to afirst symbol 502 and a second symbol 504, in the first slot for normalcyclic prefix (NCP), and the SSSS 402 is mapped to a fourth symbol 506and a fifth symbol 508, in the second slot for NCP.

Both the NB-IoT primary synchronization signals (NPSS) and NB-IoTsecondary synchronization signals (NSSS) are assigned to a single RB.The NPSS is based on a concatenation of a base sequence combined with acode cover which is 11 symbols long per sequence and 11 sequences areconcatenated.

The base sequence of the NSSS may be represented by a short ZC sequenceas determined by Equation (3) as follows:

$\begin{matrix}{{Z_{k} = {\exp ( \frac{{- {ju}}\; \pi \; {k( {k + 1} )}}{11} )}},{u = {5\mspace{14mu} ( {{root}\mspace{14mu} {ID}} )}}} & (3)\end{matrix}$

Where u is a root ID of the ZC sequence and k is the subcarrier indexwhose value ranges from 0 to 10, or equivalently the ZC sequence index.

The code cover includes a binary sequence and may be represented inEquation (4) as follows:

S _({1:11})=[1 1 1 1 −1 −1 1 1 1 −1 1]  (4)

FIG. 6A illustrates a mapping of primary synchronization signals in anarrow band Internet of things (IoT) communication network, according toan embodiment of the present disclosure.

FIG. 6B illustrates a mapping of primary synchronization signals in anarrow band Internet of things (IoT) communication network, according toanother embodiment of the present disclosure.

Referring to FIGS. 6A and 6B, the NPSS sequence begins at the fourthOFDM symbol 600 (which is the number 3 symbol since the numbering beginsfrom 0) and includes subsequent symbols up to and including thethirteenth OFDM symbol 602 in a subframe. The NPSS sequences of FIGS. 6Aand 6B are examples and the present disclosure is not limited thereto.

In an embodiment of the present disclosure, the NSSS is composed of afrequency domain ZC sequence with a length of 131 and a binaryscrambling sequence. In addition, a time domain cyclic shift is appliedto the NSSS sequence. The NSSS may be determined by Equation (5) asfollows:

$\begin{matrix}{{{NSSS}(n)} = {e^{- \frac{j\; \pi \; {r_{p}{({n^{\prime}{({n^{\prime} + 1})}})}}}{N_{ZC}}}{C_{S_{p}}(n)}e^{- \frac{j\; 2\pi \; l_{q}n}{d_{\max}}}}} & (5)\end{matrix}$

where n_(ZC) is the ZC sequence length, r_(p) is the ZC root ID, n′ isthe ZC sequence index, C_(S) _(p) is the Hadamard sequence definedbelow, d_(max) is the cyclic shift length which is constant to 132 andalso described below.

The ZC sequence used to generate the NSSS may be determined by Equation(6) as follows:

$\begin{matrix}e^{- \frac{j\; \pi \; {r_{p}{({n^{\prime}{({n^{\prime} + 1})}})}}}{N_{ZC}}} & (6)\end{matrix}$

where r_(p)=mod (CID,126)+3, N_(ZC)=131 and n′ is the ZC sequence index.

The binary Hadamard sequence used to generate the NSSS may be determinedby Equation (7) as follows:

C _(S) _(p) (n)=Hadamard_(S) _(p) ^(128×128)(mod(n,128))  (7)

The cyclic shift used to generate the NSSS may be determined by Equation(8) as follows:

$\begin{matrix}e^{- \frac{j\; 2\pi \; l_{q}n}{d_{\max}}} & (8)\end{matrix}$

where d_(max)=132, l₀=0, l₁=33, l₂=66, l₃=99

FIG. 7A illustrates a mapping of secondary synchronization signals in anarrow band Internet of things (IoT) communication network, according toan embodiment of the present disclosure.

FIG. 7B illustrates a mapping of secondary synchronization signals in anarrow band Internet of things (IoT) communication network, according toanother embodiment of the present disclosure.

Referring to FIGS. 7A and 7B, the NSSS is mapped to the last 11 OFDMsymbols 700 in subframe 702 of every other frame, and is mapped to full12 subcarriers 704.

In an embodiment of the present disclosure, backwards and forwardscompatibility is maintained between existing versions of LTE and futureversions of LTE and NR. Interoperability is maintained between differentversions of communication standards and between UEs and base stationssupporting different feature sets. Embodiments of the present disclosuremaximize the amount of time and frequency resources that may be utilizedflexibly or that may be left unused without causing backwardcompatibility issues. In addition, unused resources may be reserved forfuture use, the transmission of always-on signals may be minimized, andsignals and channels for physical layer functions are confined toconfigurable and allocable time and frequency resources.

In NR access technology, multiple frequency and time components usingdifferent numerologies (numerologies refers to the OFDM configuration interms of sub-carrier spacing, symbol duration, cyclic prefix, resourceblock size, etc.) may share a universal synchronization signal. Theuniversal synchronization signal refers to the signal itself and thetime and frequency resources used to transmit the universalsynchronization signal.

NR access technology enables multiple communication services includingmMTC which supports a large number of devices in machine typecommunications, URLLC applications having high reliability and lowlatency requirements, direct UE to UE type communications such as deviceto device (D2D) and vehicle to vehicle (V2V), narrowband services suchas IoT, and eMBB for high data throughput applications. NR enablesforward and backward compatibility and interoperability for itssupported services through flexible configuration of resourceallocations and the use of universal synchronization signals.

According to an embodiment of the present disclosure, the universalsynchronization signal may be flexibly configured and used amongmultiple communication services such as eMBB, URLLC, D2D, V2V, mMTC, andIoT. USS enables a common structure of synchronization signals which maybe shared among multiple communication services rather than differentsynchronization signals, such as those under LTE and NB-IoT, whichrequire assigning different synchronization signals with differentlocations of RBs.

In an embodiment of the present disclosure, the mother code is definedas a short ZC sequence or a constant amplitude zero autocorrelationsequence (CAZAC) combined with single or multiple orthogonal codecovers. The mother code may be extended to m RBs and n OFDM symbols withdifferent code covers. The mother code corresponds to a minimum resourceunit for NR such as 1 RB in 1 subframe with minimum numerology, such asa bandwidth of 15 kHz. The mother code and/or its extension are sharedamong multiple services within NR. For example, in eMBB or LTE, themother code uses m RBs and n OFDM symbols for UPSS with code coversassigned to (m, n) grid patterns. In NB-IoT or IoT, the mother code uses1 RB and n OFDM symbols shared with eMBB or LTE. In addition, IoT mayassign more synchronization signals in the dedicated RB. Thesesynchronization signals would not affect other services since the RB isexclusively assigned to IoT. The m RBs are not necessarily contiguous atthe central RBs and a part of m RBs may be used for a specific purposeproviding flexibility for multiplexing different numerologies in thesame carrier to further enable network operators to accommodate futurecommunication services.

FIG. 8 illustrates a mapping of universal synchronization signals formultiple new radio communication services, according to anotherembodiment of the present disclosure.

Referring to FIG. 8, a mapping of frequency and time resources for USSis shown in which m=6 and n=1, a short ZC sequence with a length of 11serves as a base sequence, and a code cover sequence of length in isapplied over m RBs. Here, RB 6 800 is assigned to another service, suchas IoT, so that other dedicated synchronization symbols are added to theRB, while the number five symbol 802 (the first symbol is the numberzero symbol) serves as a shared synchronization signal.

In an embodiment of the present disclosure, the peak to average powerratio (PAPR) is considered since the UPSS could be used for all serviceswithin NR access technology. The PAPR depends on the code cover as wellas the base sequence. Different code covers may determine differentlevels of PAPR.

In an embodiment of the present disclosure, the NR transceiver 180transmits the universal synchronization signals to the transceiver 113of the electronic device 110. The transceiver 113 includes a receiverwhich receives and detects the universal synchronization signals. Thesuccessful detection of the universal synchronization signals occurswhen a number of candidate peaks of cross-correlation are extracted(e.g., 1, 2, 4, 8, 16, 32, and 64) and one of the sampled peaks iswithin +/−5 sample points of true timing. True timing may be indicatedby the index in which the universal synchronization signal sequencebegins in the time domain.

The receiver detection of universal synchronization signals in an eMBBor LTE receiver may include a full correlation implementation in which asequence is spread over m RBs as a single sequence. The correlation maybe determined by Equation (9) below:

f(t)=|Σ_(n=0) ^(N-1) r _(n)(t)c(n)*|  (9)

where N is the fast fourier transform (FFT) size, c(n) is a UPSS timedomain signal obtained from mN_(SC) subcarriers with N FFT blocks, t isthe incoming sample index in the receive buffer, and n is the sampleindex within a sliding window of size N.

The receiver detection performance of universal synchronization signalsin an eMBB or LTE receiver may also include implementation as a doublecorrelation, which exploits the fact that a base sequence is repeatedover m RBs. The double correlation may be determined by Equations (10)and (11) below:

$\begin{matrix}{{{f_{k}(t)} = {\sum\limits_{n = 0}^{{N\text{/}m} - 1}\; {{r_{{nm} + k}(t)}{c( {{nm} + k} )}^{*}}}}{and}} & (10) \\{{f(t)} = {{\sum\limits_{k = 0}^{m - 2}\; {{f_{k}(t)}{f_{k + 1}(t)}^{*}}}}} & (11)\end{matrix}$

where N is the FFT size, c(n) is a UPSS time domain signal obtained frommN_(SC) subcarriers with N FFT blocks, t is the incoming sample index inthe receive buffer, n is the sample index within a sliding window ofsize N, m is the number of RBs, and k is the cross-correlationsubsequence index.

The receiver detection of universal synchronization signals in an NB-IoTreceiver may include the same procedure as an NB-IoT detection procedurewith m=6, and n=1.

In an embodiment of the present disclosure, the USSS provides astructure for synchronization signals that may carry a physical cellidentifier (PCID) and frame timing, while providing a universalstructure among multiple NR access technologies enablinginteroperability across those technologies.

The USSS carries information including PCID and frame timing. A portionof the PCID and frame timing information may also be carried by theUPSS. The total amount of information that USSS (+UPSS) needs to carryis 504 PCIDs×4 (in the case of NB-IoT for frame timing to determine theindex where the USSS begins) or 504 PCIDs×2 (in the case of LTE slotindex of 2 slots per subframe).

In an embodiment of the present disclosure, the candidate resourceswhich may be required to carry PCID and frame timing may include thoselisted below for UPSS:

A root ID (RID), which may also be referred to as a root index, whichmay include a base sequence length of 11 and the twelfth resourceelement (RE) is identical to the first RE for a circular operation. AnRID ranging from 1 to 10 may generate different base sequences;

-   -   Cyclic shifts (CS) are not considered in order to reduce        implementation complexity; and    -   Only fixed binary scrambling sequences are used.

In an embodiment of the present disclosure, the candidate resourceswhich may be required to carry PCID and frame timing may include thoselisted below for USSS:

-   -   The same root ID used in UPSS is used for USSS in which 10        different base sequences are possible;    -   Cyclic shifts are supported. When a ZC sequence with a length of        11 is used, each sequence may be cyclic-shifted resulting in 11        different sequences being available;    -   Binary scrambling sequences are determined based on 2 different        cases differing by the sequence in which the scrambling        sequences are determined:        -   Case 1: The eMBB scrambling sequence is determined first,            then the NB-IoT scrambling sequence is determined.            -   For eMBB: Over m RBs and n symbols result in 2^(mn)                different scrambling sequences being available.            -   For NB-IoT: n symbols are shared with eMBB. Therefore,                over 11−n symbols and 2^(11-n) different scrambling                sequences are available.        -   Case 2: The NB-IoT scrambling sequence is determined first,            then the eMBB scrambling sequence is determined.            -   For NB-IoT: Over 11 symbols result in 2¹¹ different                scrambling sequences being available.            -   For eMBB: 1 RB is shared with NB-IoT. Therefore, over                m−1 RBs and n symbols result in 2^((m-1)n) different                scrambling sequences being available.

In an embodiment of the present disclosure, the total number ofcandidate resources required to carry PCID and frame timing is10×10×11×2^(mn) (or 2^(11-n)) for Case 1 defined above, and10×10×11×2^((m-1)n) (or 2¹¹) for Case 2 defined above. In both Case 1and Case 2, the present system and method minimizes variation in UPSS bychoosing a lower number of candidate RIDs for UPSS and minimizes thePAPR by choosing binary scrambling sequences.

The USSS, according to an embodiment of the present disclosure, may havethe same structure as the UPSS. The UPSS may include a fixed RID andfixed binary code cover, whereas the USSS may include the following:

-   -   10 RIDs, 2 cyclic shifts, and a scrambling sequence over 6        RBs=10×2×64=1280 combinations; or    -   10 RIDs, 2 cyclic shifts and 100 scrambling sequences=2000        combinations.

If a UE implements the NB-IoT or mMTC communication service, the UE isfreely allowed to use any of m RBs and the scrambling sequences locatedat the shared n symbols may vary according to the RB index of NB-IoT. Inthis case, the effective amount of USSS information increases by up to2n times.

Alternatively, if a UE implementing the NB-IoT or mMTC communicationservice is restricted to search its synchronization signals only at thededicated RB index, then although the synchronization signals for NB-IoTare assigned at the dedicated RB, the data signals may be transmitted atany RBs and once the synchronization signals are decoded, the hoppinginformation for data signals may be delivered to the UE using a higherlayer signaling protocol.

When the PCID and frame timing (or slot index) are determined in the NRtransceiver 180, the index of the scrambling sequence, the root ID, andcyclic shifts for the n shared symbols are determined, then the rest ofthe scrambling sequences are determined for the unshared symbols (orRBs). Since the universal synchronization signals in the NB-IoTcommunication service may be allocated to any of the RBs, the NRtransceiver 180 needs to assign different scrambling sequences to thenon-shared symbols.

When the receiver in the transceiver 113 of the electronic device 100(UE) executes the eMBB or NB-IoT communication service, the receiverneeds to search all the possible combinations of resources to detect thePCID and frame timing. However, the receiver does not need todifferentiate the shared symbols from the unshared symbols.

In an embodiment of the present disclosure, algorithms corresponding toEquations (10) and (11) of full correlation and double correlationrespectively, as described in the UPSS method above, may also be appliedto USSS.

In an embodiment of the present disclosure, the receiver detectionmethod used for NPSS may be used with many hypotheses of root ID, cyclicshifts, and scrambling sequences. The cyclic shifts in a frequencydomain may correspond to the peak detection in a time domain.

FIG. 9 is a flowchart of a method of testing a processor configured todetermine universal synchronization signals according to an embodimentof the present disclosure, where the processor is either implemented inhardware or implemented in hardware that is programmed with software.

Referring to FIG. 9, the method, at 901, forms the processor as part ofa wafer or package that includes at least one other processor. Theprocessor is configured to receive a universal synchronization signal(USS) having a universal primary synchronization signal (UPSS) and auniversal secondary synchronization signal (USSS), wherein the USS iscoded using a mother code which is extended to m resource blocks (RBs)and n orthogonal frequency division multiplexing (OFDM) symbols and acode cover of m RBs and n symbols is applied to the mother code,determine a cell identity from the USS, determine a frame timing fromthe USS, and connect a user equipment to a network using the cellidentity and the frame timing.

At 903, the method tests the processor. Testing the processor includestesting the processor and the at least one other processor using one ormore electrical to optical converters, one or more optical splittersthat split an optical signal into two or more optical signals, and oneor more optical to electrical converters.

FIG. 10 is a flowchart of a method of manufacturing a processorconfigured to determine universal synchronization signals, according toan embodiment of the present disclosure

Referring to FIG. 10, the method, at 1001, includes an initial layout ofdata in which the method generates a mask layout for a set of featuresfor a layer of the integrated circuit. The mask layout includes standardcell library macros for one or more circuit features that include aprocessor. The processor is configured to receive a universalsynchronization signal (USS) having a universal primary synchronizationsignal (UPSS) and a universal secondary synchronization signal (USSS),wherein the USS is coded using a mother code which is extended to mresource blocks (RBs) and n orthogonal frequency division multiplexing(OFDM) symbols and a code cover of m RBs and n symbols is applied to themother code, determine a cell identity from the USS, determine a frametiming from the USS, and connect a user equipment to a network using thecell identity and the frame timing.

At 1003, there is a design rule check in which the method disregardsrelative positions of the macros for compliance to layout design rulesduring the generation of the mask layout.

At 1005, there is an adjustment of the layout in which the method checksthe relative positions of the macros for compliance to layout designrules after generating the mask layout.

At 1007, a new layout design is made, in which the method, upondetection of noncompliance with the layout design rules by any of themacros, modifies the mask layout by modifying each of the noncompliantmacros to comply with the layout design rules, generates a maskaccording to the modified mask layout with the set of features for thelayer of the integrated circuit and manufactures the integrated circuitlayer according to the mask.

FIG. 11 is a flowchart of a method of connecting a user equipment to anetwork using a universal synchronization signal (USS), according to anembodiment of the present disclosure.

Referring to FIG. 11, the method, at 1101, includes coding a universalsynchronization signal (USS) having a universal primary synchronizationsignal (UPSS) and a universal secondary synchronization signal (USSS)using a mother code which is extended to m resource blocks (RBs) and northogonal frequency division multiplexing (OFDM) symbols. At 1102, themethod applies a code cover of m RBs and n OFDM symbols to the mothercode. At 1103, the method receives the universal synchronization signal(USS) having the universal primary synchronization signal (UPSS) and theuniversal secondary synchronization signal (USSS). At 1104, the methoddetermines a cell identity number based on the USS. At 1105, the methoddetermines a frame timing based on the USS. At 1106, the method connectsa user equipment to a network using the cell identity number and theframe timing.

While the present disclosure has been particularly shown and describedwith reference to certain embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present disclosure as defined by the appended claims and theirequivalents.

What is claimed is:
 1. A method, comprising: receiving a first universalsynchronization signal (USS) for a first communication service;receiving a second USS for a second communication service; determining acell identity number for the first communication service based on thefirst USS; determining a frame timing for the first communicationservice based on the first USS; and connecting a user equipment to anetwork via the first communication service using the cell identitynumber for the first communication service and the frame timing for thefirst communication service, wherein the first USS is coded usingrepetitions of a first scrambling sequence and an un-punctured basesequence, and wherein the second USS is coded using repetitions of theun-punctured base sequence and a second scrambling sequence.
 2. Themethod of claim 1, further comprising: determining a cell identitynumber for the second communication service based on the second USS;determining a frame timing for the second communication service based onthe second USS; and connecting the user equipment to the network via thesecond communication service using the cell identity number for thesecond communication service and the frame timing for the secondcommunication service.
 3. The method of claim 1, wherein theun-punctured base sequence has a length that is within one resourceblock and one symbol.
 4. The method of claim 1, wherein the un-puncturedbase sequence comprises a Zadoff-Chu (ZC) sequence with a fixed rootindex value.
 5. The method of claim 1, wherein the un-punctured basesequence comprises a Zadoff-Chu (ZC) sequence with a root index valuefrom 1 to a length of the Zadoff-Chu (ZC) sequence minus
 1. 6. Themethod of claim 1, wherein the un-punctured base sequence comprises aZadoff-Chu (ZC) sequence with multiple root indexes and a cyclic shift.7. The method of claim 1, wherein the un-punctured base sequencecomprises a Zadoff-Chu (ZC) sequence with a length of 11 resourceelements (REs).
 8. The method of claim 1, wherein the firstcommunication service is at least one of enhanced mobile broad band(eMBB), massive machine type communication (mMTC), ultra reliable lowlatency communication (URLLC), and narrow-band Internet of things(NB-IoT).
 9. The method of claim 1, wherein the first scramblingsequence comprises a binary scrambling sequence corresponding to thefirst communication service.
 10. The method of claim 9, wherein thesecond scrambling sequence comprises a binary scrambling sequencecorresponding to the second communication service.
 11. An apparatus,comprising: a transceiver; and a processor configured to: receive, withthe transceiver, a first universal synchronization signal (USS) for afirst communication service; receive, with the transceiver, a second USSfor a second communication service; determine a cell identity number forthe first communication service based on the first USS; determine aframe timing for the first communication service based on the first USS;and connect the apparatus to a network via the first communicationservice using the cell identity number for the first communicationservice and the frame timing for the first communication service,wherein the first USS is coded using repetitions of a first scramblingsequence and an un-punctured base sequence, and wherein the second USSis coded using repetitions of the un-punctured base sequence and asecond scrambling sequence.
 12. The apparatus of claim 11, wherein theprocessor is further configured to: determine a cell identity number forthe second communication service based on the second USS; determine aframe timing for the second communication service based on the secondUSS; and connect the apparatus to the network via the secondcommunication service using the cell identity number for the secondcommunication service and the frame timing for the second communicationservice.
 13. The apparatus of claim 11, wherein the un-punctured basesequence has a length that is within one resource block and one symbol.14. The apparatus of claim 11, wherein the un-punctured base sequencecomprises a Zadoff-Chu (ZC) sequence with a fixed root index value. 15.The apparatus of claim 11, wherein the un-punctured base sequencecomprises a Zadoff-Chu (ZC) sequence with a root index value from 1 to alength of the Zadoff-Chu (ZC) sequence minus
 1. 16. The apparatus ofclaim 11, wherein the un-punctured base sequence comprises a Zadoff-Chu(ZC) sequence with multiple root indexes and a cyclic shift.
 17. Theapparatus of claim 11, wherein the un-punctured base sequence comprisesa Zadoff-Chu (ZC) sequence with a length of 11 resource blocks.
 18. Theapparatus of claim 11, wherein the first communication service is atleast one of enhanced mobile broad band (eMBB), massive machine typecommunication (mMTC), ultra reliable low latency communication (URLLC),and narrow-band Internet of things (NB-IoT).
 19. The apparatus of claim11, wherein the first scrambling sequence comprises a binary scramblingsequence corresponding to the first communication service.
 20. Theapparatus of claim 19, wherein the second scrambling sequence comprisesa binary scrambling sequence corresponding to the second communicationservice.